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Supratemporal
The supratemporal bone is a paired Skull, cranial bone present in many Tetrapod, tetrapods and Tetrapodomorpha, tetrapodomorph fish. It is part of the temporal region (the portion of the skull roof behind the eyes), usually lying medial (inwards) relative to the Squamosal bone, squamosal and lateral (outwards) relative to the Parietal bone, parietal and/or postparietal. It may also contact the Postorbital bone, postorbital or Intertemporal bone, intertemporal (which lie forwards), or Tabular bone, tabular (which lies backwards), when those bones are present. The supratemporal is a common component of the skull in many extinct Amphibian, amphibians, though it is apparently absent in the lightweight skulls of living Lissamphibia, lissamphibians (frogs and salamanders). Embryology, Embryological studies of Salamander, salamanders suggests that the supratemporal fuses with the squamosal in early development. A separate supratemporal was retained by early Synapsid, synapsids and Reptile, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intertemporal Bone
The intertemporal bone is a paired Skull, cranial bone present in certain Sarcopterygii, sarcopterygians (lobe-finned fish) and extinct amphibian-Evolutionary grade, grade tetrapods. It lies in the rear part of the skull, behind the eyes. Many lineages of four-limbed vertebrates ("tetrapods" in the broad sense) have lost the intertemporal bone. These include ''Acanthostega'', ''Ichthyostega, Icththyostega'', Colosteidae, colosteids (except for a vestigial intertemporal in ''Greererpeton''), Diadectomorpha, diadectomorphs, Lepospondyli, lepospondyls, and amniotes. Lissamphibians (i.e. modern amphibians like frogs, salamanders, and caecilians) also lack an intertemporal. Most Temnospondyli, temnospondyls lack an intertemporal, though several early groups like Edopoidea, edopoids, Dvinosauria, dvinosaurs, and various other basal taxa retain the bone. Tetrapod groups which do possess an intertemporal typically have it contact the parietal bone along its inner edge, the Postfrontal bone ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Postparietal
Postparietals are cranial bones present in fish and many Tetrapod, tetrapods. Although initially a pair of bones, many lineages possess postparietals which were fused into a single bone. The postparietals were Dermal bone, dermal bones situated along the midline of the skull, behind the Parietal bone, parietal bones. They formed part of the rear edge of the skull roof, and the lateral edge of each postparietal often contacts the Tabular bone, tabular and Supratemporal bone, supratemporal bones. In fish, the postparietals are elongated, typically the largest components of the skull roof. Tetrapods possessed shorter postparietals, which were reduced further and shifted towards the Neurocranium, braincase in Amniote, amniotes. At several points in synapsid evolution, the postparietals fused to each other and the tabulars during Embryology, embryological development. This fusion produces the interparietal bone, which is inherited by Mammal, mammals. Postparietals are common in extinct Am ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eunotosaurus
''Eunotosaurus'' (''Latin (language), Latin'': Stout-backed lizard) is an extinct genus of amniote, possibly a close relative of turtles. ''Eunotosaurus'' lived in the late Middle Permian (Capitanian stage) and fossils can be found in the Karoo Supergroup of South Africa and Malawi. ''Eunotosaurus'' resided in the swamps of what is now southern Africa. Its ribs were wide and flat, forming broad plates similar to a primitive turtle shell, and the vertebrae were nearly identical to those of some turtles. Accordingly, it is often considered as a possible transitional fossil between turtles and their prehistoric ancestors. However, it is possible that these turtle-like features evolved independently of the same features in turtles, since other anatomical studies and phylogenetic analyses suggest that ''Eunotosaurus'' may instead have been a parareptile, an early-diverging neodiapsid unrelated to turtles, or a synapsid. Description ''Eunotosaurus'' reached up to in total body length. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proganochelys
''Proganochelys'' is a genus of extinct, primitive stem-turtle. ''Proganochelys'' was named by Georg Baur in 1887 as the oldest turtle in existence at the time. The name ''Proganochelys'' comes from the Greek language, Greek word ''ganos'' meaning 'brightness', combined with prefix ''pro'', 'before', and Greek language, Greek base ''chelys'' meaning 'turtle'. ''Proganochelys'' is believed to have been around 1 meter in size and herbivorous in nature. ''Proganochelys'' had been known as the most primitive stem-turtle for over a century, until the novel discovery of ''Odontochelys'' in 2008. ''Odontochelys'' and ''Proganochelys'' share unique primitive features that are not found in ''Casichelydia'', such as tooth-like structures on the pterygoid bone, pterygoid and vomer and a plate-like coracoid. ''Proganochelys quenstedtii'' is the only known species of this genus and is among the oldest known Pantestudines, stem-turtle species with a complete shell discovered to date, known fro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Skull
The skull, or cranium, is typically a bony enclosure around the brain of a vertebrate. In some fish, and amphibians, the skull is of cartilage. The skull is at the head end of the vertebrate. In the human, the skull comprises two prominent parts: the neurocranium and the facial skeleton, which evolved from the first pharyngeal arch. The skull forms the frontmost portion of the axial skeleton and is a product of cephalization and vesicular enlargement of the brain, with several special senses structures such as the eyes, ears, nose, tongue and, in fish, specialized tactile organs such as barbels near the mouth. The skull is composed of three types of bone: cranial bones, facial bones and ossicles, which is made up of a number of fused flat and irregular bones. The cranial bones are joined at firm fibrous junctions called sutures and contains many foramina, fossae, processes, and sinuses. In zoology, the openings in the skull are called fenestrae, the most ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reptile
Reptiles, as commonly defined, are a group of tetrapods with an ectothermic metabolism and Amniotic egg, amniotic development. Living traditional reptiles comprise four Order (biology), orders: Testudines, Crocodilia, Squamata, and Rhynchocephalia. About 12,000 living species of reptiles are listed in the Reptile Database. The study of the traditional reptile orders, customarily in combination with the study of modern amphibians, is called herpetology. Reptiles have been subject to several conflicting Taxonomy, taxonomic definitions. In Linnaean taxonomy, reptiles are gathered together under the Class (biology), class Reptilia ( ), which corresponds to common usage. Modern Cladistics, cladistic taxonomy regards that group as Paraphyly, paraphyletic, since Genetics, genetic and Paleontology, paleontological evidence has determined that birds (class Aves), as members of Dinosauria, are more closely related to living crocodilians than to other reptiles, and are thus nested among re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amphibian Anatomy
Amphibians are ectothermic, anamniote, anamniotic, tetrapod, four-limbed vertebrate animals that constitute the class (biology), class Amphibia. In its broadest sense, it is a paraphyletic group encompassing all Tetrapod, tetrapods, but excluding the amniotes (tetrapods with an amniotic membrane, such as modern reptiles, birds and mammals). All extant taxon, extant (living) amphibians belong to the monophyletic subclass (biology), subclass Lissamphibia, with three living order (biology), orders: Anura (frogs and toads), Urodela (salamanders), and Gymnophiona (caecilians). Evolved to be mostly semiaquatic, amphibians have adapted to inhabit a wide variety of habitats, with most species living in freshwater ecosystem, freshwater, wetland or terrestrial ecosystems (such as riparian woodland, fossorial and even arboreal habitats). Their biological life cycle, life cycle typically starts out as aquatic animal, aquatic larvae with gills known as tadpoles, but some species have devel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fish Anatomy
Fish anatomy is the study of the form or Morphology (biology), morphology of fish. It can be contrasted with fish physiology, which is the study of how the component parts of fish function together in the living fish. In practice, fish anatomy and fish physiology complement each other, the former dealing with the structure of a fish, its organs or component parts and how they are put together, such as might be observed on the dissecting table or under the microscope, and the latter dealing with how those components function together in living fish. The anatomy of fish is often shaped by the physical characteristics of water, the medium in which fish live. Water is much density, denser than air, holds a relatively small amount of dissolved oxygen, and absorbs more light than air does. The body of a fish is divided into a head, trunk and tail, although the divisions between the three are not always externally visible. The skeleton, which forms the support structure inside the fish ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turtle
Turtles are reptiles of the order (biology), order Testudines, characterized by a special turtle shell, shell developed mainly from their ribs. Modern turtles are divided into two major groups, the Pleurodira (side necked turtles) and Cryptodira (hidden necked turtles), which differ in the way the head retracts. There are 360 living and recently extinct species of turtles, including land-dwelling tortoises and freshwater terrapins. They are found on most continents, some islands and, in the case of sea turtles, much of the ocean. Like other Amniote, amniotes (reptiles, birds, and mammals) they breathe air and do not lay eggs underwater, although many species live in or around water. Turtle shells are made mostly of bone; the upper part is the domed Turtle shell#Carapace, carapace, while the underside is the flatter plastron or belly-plate. Its outer surface is covered in scale (anatomy), scales made of keratin, the material of hair, horns, and claws. The carapace bones deve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mammal
A mammal () is a vertebrate animal of the Class (biology), class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three Evolution of mammalian auditory ossicles, middle ear bones. These characteristics distinguish them from reptiles and birds, from which their ancestors Genetic divergence, diverged in the Carboniferous Period over 300 million years ago. Around 6,640 Neontology#Extant taxon, extant species of mammals have been described and divided into 27 Order (biology), orders. The study of mammals is called mammalogy. The largest orders of mammals, by number of species, are the rodents, bats, and eulipotyphlans (including hedgehogs, Mole (animal), moles and shrews). The next three are the primates (including humans, monkeys and lemurs), the Artiodactyl, even-toed ungulates (including pigs, camels, and whales), and the Carnivora (including Felidae, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bird
Birds are a group of warm-blooded vertebrates constituting the class (biology), class Aves (), characterised by feathers, toothless beaked jaws, the Oviparity, laying of Eggshell, hard-shelled eggs, a high Metabolism, metabolic rate, a four-chambered heart, and a strong yet lightweight Bird skeleton, skeleton. Birds live worldwide and range in size from the bee hummingbird to the common ostrich. There are over 11,000 living species and they are split into 44 Order (biology), orders. More than half are passerine or "perching" birds. Birds have Bird wing, wings whose development varies according to species; the only known groups without wings are the extinct moa and elephant birds. Wings, which are modified forelimbs, gave birds the ability to fly, although further evolution has led to the Flightless bird, loss of flight in some birds, including ratites, penguins, and diverse endemism, endemic island species. The digestive and respiratory systems of birds are also uniquely a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crocodilia
Crocodilia () is an order of semiaquatic, predatory reptiles that are known as crocodilians. They first appeared during the Late Cretaceous and are the closest living relatives of birds. Crocodilians are a type of crocodylomorph pseudosuchian, a subset of archosaurs that appeared about 235 million years ago and were the only survivors of the Triassic–Jurassic extinction event. While other crocodylomorph groups further survived the Cretaceous–Paleogene extinction event, notably sebecosuchians, only the crocodilians have survived into the Quaternary. The order includes the true crocodiles (family Crocodylidae), the alligators and caimans (family Alligatoridae), and the gharial and false gharial (family Gavialidae). Although the term "crocodiles" is sometimes used to refer to all of these families, the term "crocodilians" is less ambiguous. Extant crocodilians have flat heads with long snouts and tails that are compressed on the sides, with their eyes, ears, and n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
